Watkins’s middle name remains a matter of controversy. Some generally reliable sources give “Emmons,” while other equally reliable sources give “Eugene.” Because Watkins’s father had a friend named Clarence Emmons and Emmons is a common family name in the region, most photographic historians weigh in on the side of “Emmons.” Yet his daughter, Julia, insisted that her father’s middle name was “Eugene.” According to Peter Palmquist, author of the exhibition catalog produced for a 1980s exhibition “Carleton E. Watkins, Photographer of the American West,” the only known primary source document is an 1879 voter registry from San Francisco, which lists a photographer by the name of Carleton Eugene Watkins. No birth or baptismal records have been found.